CyberSecBulletin
CVE-2026-90651NVD status: Deferred

Socket Firewall: Improper Certificate Validation

CVE-2026-90651 is a high-severity improper certificate validation vulnerability in Socket Firewall from Socket, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 2.0.0 as the first without the flaw, so updating Socket Firewall to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Socket Firewall to 2.0.0 or a later version.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
SocketSocket Firewallbefore 2.0.02.0.0

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
LowSome restricted data can be read.
Integrity
HighData or code can be modified at will.
Availability
LowPerformance or availability is reduced.

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:L. Scored by CNA (mitre.org).

Official description

Socket Firewall (socketdev/socket-registry-firewall) in registry mode before 2.0.0 does not verify upstream TLS certificates by default. When the api_ssl_verify and upstream_ssl_verify configuration keys are omitted from socket.yml, the generated configuration sets SOCKET_API_SSL_VERIFY='false' and UPSTREAM_SSL_VERIFY='false', and the OpenResty/Lua HTTP client used for outbound requests accepts any certificate, including self-signed and otherwise untrusted certificates, without validating the chain. An attacker positioned to intercept traffic between Socket Firewall and the Socket API or an upstream package registry can present a crafted certificate and modify responses in transit, including substituting malicious package content or altering the allow/block decisions the firewall enforces. Setting api_ssl_verify: true and upstream_ssl_verify: true enables verification; however, in versions before 1.1.334, the generated nginx configuration did not emit lua_ssl_trusted_certificate, and thus verification could not be used successfully without manually patching the generated configuration. Version 2.0.0 changes the default for both settings to true.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Certificate Validation

The product does not validate, or incorrectly validates, a certificate.

How developers prevent this class of flaw

  • Certificates should be carefully managed and checked to assure that data are encrypted with the intended owner's public key.
  • If certificate pinning is being used, ensure that all relevant properties of the certificate are fully validated before the certificate is pinned, including the hostname.

More Improper Certificate Validation vulnerabilities (CWE-295)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Improper Certificate Validation vulnerabilities

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